In the villages of Dulamayo Selatan, traditional agroforestry systems are callled llengi. The structure of these forests resembles natural forest, and provide numerous products to local people. There are six different kinds of ilengi agroforestry, which are planted with different species according to the products which farmers aim to harvest, including food, medicine and timber. The purpose of this study is to characterise ilengi, identify the diversity and richness of tree species in this forest characteristics identify, farmers' knowledge about the selection of tree species, and their pereferences for various plants and tree species ilengi. The methods included analyzing the diversity index and the density of tree species, tree species richness index, basal area, and the Local User Value Index (LUVI).